/* 
  China Travel Explorer - Main Stylesheet
  Version: 1.0
  Author: China Travel Team
*/

/* ===== VARIABLES ===== */
:root {
  /* Color Palette */
  --primary-red: #d32f2f;
  --primary-red-dark: #b71c1c;
  --primary-green: #388e3c;
  --primary-green-dark: #2e7d32;
  --primary-blue: #1976d2;
  --primary-blue-dark: #0d47a1;
  --accent-orange: #ff9800;
  --accent-orange-dark: #f57c00;
  --accent-yellow: #ffc107;
  
  /* Neutral Colors */
  --dark-color: #212121;
  --medium-color: #666;
  --light-color: #f5f5f5;
  --white: #ffffff;
  --gray-100: #f8f9fa;
  --gray-200: #e9ecef;
  --gray-300: #dee2e6;
  --gray-400: #ced4da;
  --gray-500: #adb5bd;
  
  /* Typography */
  --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-heading: 'Georgia', 'Times New Roman', serif;
  --font-size-base: 16px;
  --line-height-base: 1.6;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  
  /* Borders & Shadows */
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 15px;
  --border-radius-xl: 25px;
  --box-shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.1);
  --box-shadow-md: 0 5px 20px rgba(0, 0, 0, 0.15);
  --box-shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.2);
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ===== RESET & BASE ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--dark-color);
  background-color: var(--white);
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--spacing-sm);
}

a {
  color: var(--primary-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-blue-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ===== UTILITY CLASSES ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.p-1 { padding: var(--spacing-xs); }
.p-2 { padding: var(--spacing-sm); }
.p-3 { padding: var(--spacing-md); }
.p-4 { padding: var(--spacing-lg); }
.p-5 { padding: var(--spacing-xl); }

.bg-light { background-color: var(--light-color); }
.bg-white { background-color: var(--white); }
.bg-primary { background-color: var(--primary-red); color: var(--white); }
.bg-secondary { background-color: var(--primary-blue); color: var(--white); }
.bg-success { background-color: var(--primary-green); color: var(--white); }

.text-primary { color: var(--primary-red); }
.text-secondary { color: var(--primary-blue); }
.text-success { color: var(--primary-green); }
.text-warning { color: var(--accent-orange); }
.text-muted { color: var(--medium-color); }

.rounded { border-radius: var(--border-radius-md); }
.rounded-lg { border-radius: var(--border-radius-lg); }
.rounded-xl { border-radius: var(--border-radius-xl); }

.shadow { box-shadow: var(--box-shadow-sm); }
.shadow-lg { box-shadow: var(--box-shadow-lg); }

/* ===== NAVIGATION ===== */
.navbar {
  background-color: var(--white);
  padding: var(--spacing-sm) 0;
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: var(--box-shadow-sm);
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  padding: var(--spacing-xs) 0;
  box-shadow: var(--box-shadow-md);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  text-decoration: none;
}

.logo-icon {
  font-size: 2rem;
  color: var(--primary-red);
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--dark-color);
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
}

.nav-links a {
  color: var(--dark-color);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-normal);
}

.nav-links a:hover {
  color: var(--primary-red);
  background-color: rgba(211, 47, 47, 0.1);
}

.nav-links a.active {
  color: var(--primary-red);
  background-color: rgba(211, 47, 47, 0.1);
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius-xl);
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-normal);
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background-color: var(--primary-red);
  color: var(--white);
}

.btn-primary:hover {
  background-color: var(--primary-red-dark);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(211, 47, 47, 0.3);
}

.btn-secondary {
  background-color: var(--primary-blue);
  color: var(--white);
}

.btn-secondary:hover {
  background-color: var(--primary-blue-dark);
  transform: translateY(-2px);
}

.btn-success {
  background-color: var(--primary-green);
  color: var(--white);
}

.btn-success:hover {
  background-color: var(--primary-green-dark);
  transform: translateY(-2px);
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--primary-red);
  color: var(--primary-red);
}

.btn-outline:hover {
  background-color: var(--primary-red);
  color: var(--white);
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 1.1rem;
}

.btn-small {
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: 0.9rem;
}

/* ===== FORMS ===== */
.form-group {
  margin-bottom: var(--spacing-md);
}

.form-label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-weight: 600;
  color: var(--dark-color);
}

.form-control {
  width: 100%;
  padding: var(--spacing-sm);
  border: 2px solid var(--gray-300);
  border-radius: var(--border-radius-md);
  font-size: 1rem;
  transition: border-color var(--transition-normal);
  font-family: var(--font-primary);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(25, 118, 210, 0.1);
}

.form-control.error {
  border-color: var(--primary-red);
}

.form-text {
  display: block;
  margin-top: var(--spacing-xs);
  font-size: 0.875rem;
  color: var(--medium-color);
}

.form-text.error {
  color: var(--primary-red);
}

/* ===== CARDS ===== */
.card {
  background-color: var(--white);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--box-shadow-sm);
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--box-shadow-md);
}

.card-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.card-body {
  padding: var(--spacing-md);
}

.card-title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
}

.card-text {
  color: var(--medium-color);
  margin-bottom: var(--spacing-md);
}

/* ===== SECTIONS ===== */
.section {
  padding: var(--spacing-xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title {
  position: relative;
  display: inline-block;
  margin-bottom: var(--spacing-sm);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background-color: var(--primary-red);
  border-radius: 2px;
}

.section-description {
  max-width: 700px;
  margin: 0 auto;
  color: var(--medium-color);
}

/* ===== FOOTER ===== */
.footer {
  background-color: var(--dark-color);
  color: var(--white);
  padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.footer-section h3 {
  color: var(--white);
  margin-bottom: var(--spacing-md);
  font-size: 1.25rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-xs);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--accent-orange);
}

.social-links {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  text-decoration: none;
  transition: background-color var(--transition-normal);
}

.social-link:hover {
  background-color: var(--primary-red);
}

.copyright {
  text-align: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.875rem;
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
  :root {
    --font-size-base: 15px;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.5rem; }
  
  .nav-links {
    display: none;
  }
  
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .section {
    padding: var(--spacing-lg) 0;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 576px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  
  .btn-large {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 1rem;
  }
  
  .logo-text {
    font-size: 1.25rem;
  }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.animate-fade-in {
  animation: fadeIn 0.8s ease forwards;
}

.animate-slide-left {
  animation: slideInLeft 0.8s ease forwards;
}

.animate-slide-right {
  animation: slideInRight 0.8s ease forwards;
}

/* ===== CUSTOM COMPONENTS ===== */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  z-index: -1;
}

.hero-background::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.7));
}

.hero-content {
  max-width: 800px;
  padding: var(--spacing-md);
  z-index: 1;
}

.rating-stars {
  color: var(--accent-orange);
  font-size: 1.2rem;
}

.price-tag {
  font-size: 2rem;
  color: var(--primary-red);
  font-weight: 700;
}

.price-tag small {
  font-size: 1rem;
  color: var(--medium-color);
  font-weight: normal;
}

/* ===== ACCESSIBILITY ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ===== PRINT STYLES ===== */
@media print {
  .navbar,
  .footer,
  .btn,
  .social-links,
  .chat-widget {
    display: none !important;
  }
  
  body {
    font-size: 12pt;
    line-height: 1.5;
  }
  
  a {
    color: #000 !important;
    text-decoration: underline !important;
  }
}